﻿#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;

long fun(int n) {
	if(n> 2)
		return(fun(n- 1) + fun(n- 2));
	else
	return(n);
}

int main() {
	int i;
	cout<<"Needs an integer: ";
	cin>>i;
	cout<<endl;
	cout<<fun(i)<<endl;
}